Locomotive driving mechanism.



S. G. THOMSON.

'LOCOMOTIVE' DRIVING MECHANISM.

APPLICATION FILED JULY ZI, 1915.

Patented. May 9, 1916.

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SAMUEL e. THOMSON, or READING, PENNSYLVANIA.

LOCOFIOTIVE DRIVING IVIECHANISM.

Specicaton of Letters Patent.

Patented May 9, 1916.

original application mea May 1s, 1915,jseria1No.as,s29. i Divided and this appiieation sled July 21, 1915.

f i l Serial No. 41,071.

To all Lo/wm 'it mag/concern.'

Be it known that I, SAMUEL G. THOMSON, a citizen ofthe UnitedStates, and resident of Reading, in the county of Berks and State of Pennsylvania, have invented a new and useful Improvement in Locomotive. Driving Mechanism, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure lis a view partly yin side elevation, partly in vertical section, and largely diagrammatic, illustrating one form` of my invention. Fig. `2 is a section on the line Il -II of Fig. 1. Fig, 3 is a side view, partly broken away, showing the piston and piston rod extension and head; and Fig. 4 is an end view of the head.

The present application is a division of my pending application Serial No. 28,829, filed May 18,1915. l l

The present invention hasrelation to an improvement in driving mechanism for locomotives, and more particularly to the novel construction of the piston rod exten sion and the'means for guiding the same.

The object of my invention is to :provide a construction of these parts in which it is possible to make them much lighter than heretofore, while at the same timethey have the proper strength. y f

Referring Lto the accompanying drawings, in which I have shown a preferred embodiment of my invention, the numeral 2 designates one of the locomotivecylinders, 3 the piston rod, 4 the piston, y5 the crosshead, 6 thel main rod connected kto the crosshead, and 7 the crosshead guides.

8 designates the piston rod extension at the front end of the cylinder 2. In accordance with my invention, I prefer to"male this extension in the form of a light tubing of substantially the same diameter as the diameter of the piston rod, and having a bushing 9 forced into its rear end. This bushing is internally threaded and is screwed to the threaded end portion 10 yof the piston rod. When tightened in this position, the tubing may be welded and thus make a very strong connection. The connection may, however, be made many other suitable way; for instance, the piston rod extension may be connected directly to the ypiston head, instead of to the piston rod. The `essential feature of the invention consists in the use of a light piece of tubing for the rod extension, rather than making it of the same forging as the piston rod, and relying on holes drilled through its center to afford lightness. Tubing of large diameter may be used without involving much metal, and great stiffness may thus be obtained with a comparatively small weight.

The piston rod extension 8 is provided with a guiding crosshead 11. This head is shown consisting of an aluminum center 12 for which the extension ySforms a core, and which is provided with facings 13 of suitable bearing metal suchas lead or babbitt. The aluminum center may be provided with recesses into which the bearin metalis cast, as indicated at 14.

The head 11 is provided with a suitable guide 15 `whi'chis in the form of an open trough, preferably of angle or' V-form,-a's shown in Fig. 2, inwhich ease'the bearing portions of thel crosshead are of corresponding form. This permits theuse of a relatively` thin plate guide, which not `only gives greatresistance to both vertical and lateral thrusts, but is comparatively light and stiff.` Preferably, the crossheadis attached to the piston rod extension in a mannerato permit rotationfof the head so that when one of its bearing surfaces becomes worn, it may be reversed edge for edge. y

Figs. `3 and 4 show another angular form of crosshead 11C, which gives substantially the same result as that shown in Fig. 2, eX- cept thatit can be brought intofour dif# ferent bearing positions. The crosshead shown in Figs. 3 and 4 can also be rotated into a number of different bearing positions. It is of decided advantage to have this head of angularform, instead of circular,

since this form prevents the cross-head from creeping around on the extension rod; also in that, in turning the head, it must be turned to a position to bring an entirely knew bearing face into play. That is to say,

by reason of its angular form, the head must stay in its original position until it is purposely shifted to an entirely new position.

While I have spoken herein of the use of aluminum in the crosshead, I intend to include by this, as well as in the claims, the use of any of the various suitable alloys of aluminum, Vsuch* as those in which smally portions of tin, copper and nickel are added,

but in which aluminum forms the main element. ,u e

My invention provides a piston rod' eX- tension and guiding means therefor, which can be made very much lighter than those heretofore in use; vwhich has the necessary strength and stiffness combined with `the reduced weight; and which also provides for bringing a fresh bearing surface of the crosshead into use without necessitating the removal and refacing of the entire head.

Y I claim:

Vl. A locomotive driving gear, comprising a cylinder, a piston therein, a piston rod for transmitting the power from the piston to the main cross head, and a projection rigidly attached to and projecting beyond the forward side of the piston, and a hollow tail rod having a rigidly secured telescopic connection with said projection, said rod carrying a guiding crossk head.

2. A locomotive driving gear, comprising a cylinder, a piston therein, a piston rod for transmitting the power from the piston to the main crosshead, said rod having a reduced portion extending into the hub of the piston and upon which the piston is secured, the end of the rod extending through the piston and terminating in a projecting portion, and a hollow tail lrod extension fitting over said projection and secured thereto with its end abutting against the hub porn tion of the piston.

3. A driving mechanism for locomotives, having a driving member comprising a piston and a piston rod, anda hollow tail rod extension telescoped over and secured to a projection from said driving member.

4L. kIn a locomotive driving mechanism, a driving member comprising al piston and piston rod, and a member projecting beyond the forward side of the piston, and a hollow tail rod extension having a rigid telescopic connection with said projecting mem" ber, said extension having a reinforced portion at the point where it joins said driving member. Y i

5. A driving mechanism for a locomotive,

having a piston, Vpiston rod extension, and a crosshead and a single concave guide for said extension, said guide being adapted to carry all the weight and side thrust of the cross-head, said crosshead having similar substantially flat upper and lower faces'and reversibly mounted on said piston rod eX- tension.

6. A driving mechanism .fori locomotives, having a piston, a piston rod extension, and a cross-head and guide for said extension, said cross-head havingy a plurality of angular bearing faces, and the cross-head being shiftable on said extension to bring= different bearing faces thereof into guiding position.

7. A driving mechanism for a locomotive, having a piston, piston rod extension, anda crosshead and guide for said extension, said crosshead adapted to turn on said piston rod extension to afford means for adjusting its alinement, said crosshead engaging substantially fiat angled faces of said guide lying entirely below aV horizontal plane through the widest portion of the cross-head.

8. A driving mechanism for a locomotive, having its piston provided with a forward extension and a crosshead rotatably mounted on said extension and provided withy a plurality of substantially fiat bearing surfaces, different surfaces being arranged to be brought into guiding position by turning the cross-head on the rod.

9. A driving mechanism for a locomotive, having a piston rod extension provided with a crosshead, said crosshead having a plurality of diderent substantially flatbearing surfaces, "and means whereby any one of said surfaces may be brought into use.

'In testimony whereof, I have hereunto' set my hand.

- SAMUEL G. THOMSON.l W'itnesses: i

HARRY EGOLF, J. I. Bns'r.

Copies of thi patent may ne obtained for ve cents each, by addressing the Gommissiqner of Patents,

' Washington, D. C. v 

